Purpose: To describe a rare case of endogenous endophthalmitis caused by Aggregatibacter aphrophilus (A. aphrophilus) in context of all previously reported cases of endophthalmitis caused by this organism. Methods: A 59-year-old male with no history of ocular trauma or surgery presented with a red, painful right eye with light perception vision. Examination showed a hypopyon, dense fibrin reaction, and cells in the anterior chamber. B-scan ultrasound showed evidence of vitritis. Broad investigations were initiated for both inflammatory and infectious etiologies. Results: The patient was diagnosed with presumed endogenous bacterial endophthalmitis as the blood cultures was positive for A. aphrophilus and vitreous cultures were negative for growth. The patient was promptly treated with intravitreal and systemic antibiotics and later underwent pars plana vitrectomy. The final visual acuity was 20/50. The patient had a prosthetic aortic valve and careful investigations had ruled out endocarditis. Conclusions: This case emphasizes the importance of early recognition, investigation, and intervention for A. aphrophilus endophthalmitis including the role of therapeutic vitrectomy. While early presentation can mimic ocular inflammatory diseases, infection from under-recognized causative organisms like A. aphrophilus, should be ruled out. Systemic and intraocular antibiotics should be started promptly in order to provide the best visual prognosis.